The present invention is directed to a static electricity suppressor, and method of making it, the static electricity suppressor being a device for emitting ions in order to eliminate or suppress static electricity in such equipment as paper machinery, textile machinery and the like.
Devices for eliminating or suppressing static electricity have long been known and widely used. For many years, such devices were made of cylindrical and tubular elements, there being typically provided a cylindrical inner conductor to which electrical energy was supplied, with a plurality of needle-like emitters joined to and/or piercing the cylindrical conductor, the emitters having their free ends in the form of points, which points were located on a common line. It was known, also to provide an encircling shield of conductive material, which was grounded, there being a transverse aperture in the shield in surrounding relationship to each of the points of each emitter. Such devices were generally known as so-called "hot bars" because they were of linear form, and because the electric potential was applied directly to the central conductor and the needle-like emitters. There was also known a so-called "shock proof" bar in which the emitters were capacitively coupled to the main supply conductor: in one embodiment, the central main conductor was ordinary insulated wire, the wire having a plurality of spaced conductive rings on it, with a needle-like emitter in direct contact with each of the conductive rings.
Later there were developed other bars in which the surrounding conductive tube was eliminated, there being used instead a channel-shaped member, which in some embodiments was used as the grounded member, while in other embodiments it was used as an electricity buss bar. While the devices, through continuous development, resulted in somewhat reduced cost, they have not achieved as low a cost as is desirable.
Further and more recent developments have been away from the above noted constructions. For example, a known static neutralizer is formed of a pair of rectangular bar sections in face-to-face contact. One of these sections was provided with fine grooves which, when the two sections were engaged, provided passages for discharge elements formed of fine resilient wire stock. A half-channel was provided in each of the rectangular sections, in which the current supply wire was located, being provided with a plurality of spaced conductive induction sleeves, each of which was engaged by a discharge element. Such construction requires threading of the induction sleeves on the wires, the provision of thin grooves, and the assemblage of fine wires in the grooves, all of which lead to an expensive construction: also, there were provided adjacent the free ends of the discharge elements grooves in the outer surfaces of the pair of bar sections, in which was positioned a ground wire. The construction was expensive because it required, in addition to the threading operations, other expensive manufacturing operations of fairly close tolerance.
Another proposal in the prior art provided an elongate base of insulating material on a side of which was a conductive discharge element of thin, flat, elongate shape having one straight edge and the opposite edge provided with a plurality of sharp emitter points, between which were smooth semi-circular areas. On the opposite side of the elongate base was a conductive ground element of thin, elongate shape. This structure was mounted in a generally U-shaped insulating housing. It was a hot bar, in that the discharge element was directly connected to a source of electricity.
Another proposal in the prior art provided an elongate laminated structure including a base strip of insulating material provided on one side with a continuous conductive strip connected to a source of electricity and on the opposite side with a plurality of ionizing elements each in the form of a generally square plate with an ionizing tip extending from it. In this construction, which was of the "shock proof" type, there was no provision for a ground.
Also known to the prior art was an electro-static charging or discharging device comprising a body of insulating material having grooves on one of its surfaces; at each end of the grooves were bores extending through the insulating material body. In these bores were inserted needles, and the body was provided with a metal element for common connection to the two rows of needles. This device, while utilizing needle-like emitters, required a number of manufacturing steps, to provide the noted grooves, or required a mold of substantial complexity, if it were to be formed by molding. Further, this device had no provision for a ground.